Gene Therapy

Question 1

Why are nice useful model organisms?

Answer 1

Small and quick to breed
Conserved gene structure and function
Test therapies and treatments

Question 2

What are the requirements for an ideal vector?

Answer 2

Safe

Immuno inert

Dividing and non-dividing uses

Targeted to cell type or tissue

Long term

Cost effective.

Question 3

What are the advantages and disadvantages of retroviruses?

Answer 3

Long term expression due to integration
High efficiency of delivery

Viruses provoke immune response
Random integration –> oncogenic activation
Max insert size = 7-8kB

Question 4

What is adenovirus?

Answer 4

Non-envelopes icosahedral virus composed of a nucleocapsid with double stranded linear genome of ~36kB.

Question 5

What are the advantages of adenoviruses and AAVs?

Answer 5

Easy / non immuno inflame or pathogenic 
High titres 
Efficient delivery / long term 
Dividing and non x2 
No integration / can integrate 
Large genes I gutless

Question 6

What have AAVs been used for so far?

Answer 6

Retinal gene disorders
Muscular dystrophy
Haemophilia

Question 7

What are the natural tropisms of;
AAV
Adenovirus
Retrovirus?

Answer 7

Bone marrow cells
Endothelial
Cancer

Question 8

Give an example of targeted expression?

Answer 8

Use tissue specific promoters in constructs

Endothelial specific promoter targets vector to endothelial cells e.g VEGFR1

Question 9

Outline how CF is being targeted?

Answer 9

Adenovirus vector
Possible to inhale vector with CFTR gene?
Clinical trials in progress
Incidence is 1 in 2500

Question 10

What trials have retroviruses undergone?

Answer 10

1990
Ex vivo human
Adenosine deaminase deficiency
SCID trial

Question 11

What two types of diseases?

Answer 11

Loss of function- transgender could work alongside e.g. CF

abnormal protein production - homologous recombination needed to replace defective gene - bother practical for gene therapy
E.g huntingtons.